1: static char help[] = "Tests application ordering.\n\n";

  3: #include <petscao.h>

  5: int main(int argc, char **argv)
  6: {
  7:   PetscMPIInt rank, size;
  8:   PetscInt    n, *ispetsc, *isapp, start, N, i;
  9:   AO          ao;

 11:   PetscFunctionBeginUser;
 12:   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
 13:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
 14:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
 15:   n = rank + 2;
 16:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));

 18:   /* create the orderings */
 19:   PetscCall(PetscMalloc2(n, &ispetsc, n, &isapp));

 21:   PetscCallMPI(MPI_Scan(&n, &start, 1, MPIU_INT, MPI_SUM, PETSC_COMM_WORLD));
 22:   PetscCallMPI(MPIU_Allreduce(&n, &N, 1, MPIU_INT, MPI_SUM, PETSC_COMM_WORLD));
 23:   start -= n;

 25:   for (i = 0; i < n; i++) {
 26:     ispetsc[i] = start + i;
 27:     isapp[i]   = N - start - i - 1;
 28:   }

 30:   /* create the application ordering */
 31:   PetscCall(AOCreateBasic(PETSC_COMM_WORLD, n, isapp, ispetsc, &ao));
 32:   PetscCall(AOView(ao, PETSC_VIEWER_STDOUT_WORLD));

 34:   /* check the mapping */
 35:   PetscCall(AOPetscToApplication(ao, n, ispetsc));
 36:   for (i = 0; i < n; i++) {
 37:     if (ispetsc[i] != isapp[i]) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "[%d] Problem with mapping %" PetscInt_FMT " to %" PetscInt_FMT "\n", rank, i, ispetsc[i]));
 38:   }
 39:   PetscCall(PetscFree2(ispetsc, isapp));

 41:   PetscCall(AODestroy(&ao));
 42:   PetscCall(PetscFinalize());
 43:   return 0;
 44: }

 46: /*TEST

 48:    test:

 50:    test:
 51:       suffix: 2
 52:       nsize: 2

 54:    test:
 55:       suffix: 3
 56:       nsize: 3

 58: TEST*/